Hello IPFire Community,
Long time, no see!
I’d like to share a solution I’ve developed for a challenge others might face when running secure web services in Orange (DMZ) networks.
The Problem
I run a personal website in my IPFire Orange network with very restrictive security policies:
- Strict geolocation blocking to prevent access from unwanted regions
- No permanent NAT forwarding on port 80 for security reasons
- TLS termination on the server (not using IPFire as a reverse proxy)
- Manual certificate renewal process that required temporarily opening port 80 and disabling geo-blocking
This manual process worked fine until recently when Let’s Encrypt stopped sending email expiration reminders. Without those notifications, I realized I needed an automated solution to prevent unexpected certificate expirations that could take my site offline.
The Constraints
My specific limitations made this challenging:
- Cannot use DNS-01 challenge method - my DNS provider doesn’t support the required TXT record automation
- Must use HTTP-01 challenge - requiring temporary port 80 access for Let’s Encrypt validation
- Security cannot be permanently compromised - geo-blocking and port 80 restrictions must be restored after renewal
- No reverse proxy setup - TLS termination happens on the DMZ server, not on IPFire
The Solution
I’ve created an automated certificate renewal handler that integrates directly with IPFire’s Web User Interface (WUI) backend. The script:
Core Functionality
- Monitors certificate expiration via secure SSH to the DMZ server
- Automatically triggers renewal when certificates are within 30 days of expiry
- Temporarily modifies firewall rules using IPFire’s native WUI commands (not raw iptables)
- Ensures complete cleanup with robust trap mechanisms that restore security settings even if the script fails
Security Features
- SSH forced-command wrapper - limits remote operations to certificate checks and renewals only
- Least-privilege sudo - grants passwordless access exclusively to specific certbot commands
- Firewall orchestration - uses IPFire’s management interface to safely modify rules
- Comprehensive logging - all actions are logged for audit trails (check with
grep CertRenewal /var/log/messages) - Automatic restoration - geo-blocking and NAT rules always return to secure baseline
Workflow
- Script runs twice daily via fcron (configurable)
- SSH check determines if renewal is needed
- If required: temporarily disables geo-blocking and enables HTTP NAT rule
- Executes
certbot renew --quietvia secure SSH wrapper - Always restores original firewall configuration via exit trap
- Logs all operations for monitoring
Trade-offs and Considerations
Strengths
Fully automated - eliminates manual intervention and forgotten renewals
Security-focused - uses least-privilege principles throughout
IPFire-native - integrates with WUI rather than bypassing it
Robust cleanup - trap mechanisms ensure firewall always returns to secure state
Auditable - comprehensive logging for troubleshooting and compliance (grep CertRenewal /var/log/messages)
Battle-tested - handles edge cases and failure scenarios
Weaknesses and Risks
Temporary security window - brief period where geo-blocking is disabled and port 80 is open
Complexity - multiple interdependent components (SSH, sudo, firewall automation)
IPFire dependency - relies on WUI command stability across updates
Network architecture specific - designed for DMZ deployments with server-side TLS termination
Requires careful setup - SSH keys, sudo configuration, and wrapper scripts must be properly configured
Important Security Note
This script temporarily reduces your firewall’s security posture during renewal. While the cleanup mechanisms are designed to be robust, they can fail.
Get the code
The complete solution, including detailed setup instructions, configuration examples, and security considerations, is available on GitHub:
Any feedback is welcome.